Phenylsulfenylchloride

Dark red liquid. Boiling point 73-75°C (1.2 kPa), 49°C (0.53 kPa). Soluble in benzene.

Phenylsulfenyl Chloride is an intermediate used in the synthesis of Tabanone (T003450), which is found in oils of Trifolium pratense L. and is a potential natural anti-oxidant.

To a flask containing 32.7 gm (0.15 mole) of diphenyl disulfide dissolved in 100 ml of dichloromethane containing 3 ml of pyridine is slowly dropwise added at room temperature 20.3 gm (0.15 mole) of freshly distilled sulfuryl chloride. After completion of the addition, the solution is stirred for an additional hour, concentrated under reduced pressure (12 mm Hg) at 25°C, and the residue distilled to afford 33 gm (76%), b.p. 49°C (4 mm Hg), of a dark red liquid.

The Journal of Organic Chemistry, 43, p. 1208, 1978 DOI: 10.1021/jo00400a041
Chemical and Pharmaceutical Bulletin, 28, p. 126, 1980 DOI: 10.1248/cpb.28.126

Phenylsulfenylchloride is extremely hygroscopic and must be carefully protected from moisture. It may be stored for months under dry inert gas in a refrigerator. However, there are two reports on the spontaneous explosion of PhSCl on storage, even in a refrigerator. It is recommended that PhSCl be prepared fresh as needed. Use in a fume hood.